Vendar lahko zakonodaja države določi daljši rok od 10 let, če je pogodbenica, na ozemlju katere je jedrska naprava odgovornega uporabnika, ukrepala, da bi krila odgovornost tega uporabnika v zvezi s katero koli tožbo za odškodnino, vloženo po preteku 10 let in med takim daljšim rokom, pod pogojem, da podaljšanje prekluzivnega roka v nobenem primeru ne vpliva na pravico do odškodnine po tej konvenciji za katero koli osebo, ki pred potekom desetletnega obdobja vloži tožbo zoper uporabnika zaradi smrti ali telesne okvare.
National legislation may, however, establish a period longer than ten years if measures have been taken by the Contracting Party in whose territory the nuclear installation of the operator liable is situated to cover the liability of that operator in respect of any actions for compensation begun after the expiry of the period of ten years and during such longer period: provided that such extension of the extinction period shall in no case affect the right of compensation under this Convention of any person who has brought an action in respect of loss of life or personal injury against the operator before the expiry of the period of ten years.